Electric switch



A l- 1932- v F. A. BLASHFIELD 1,873,259

ELECTRIC SWITCH Filed Oct. 5. 1929 llililllllll Patented Aug. 23, 1932 UNITED STATES PATENT; OFFICE FLOYD A. BLASHFIELD, OF MADISON, WISCONSIN, ASSIG-NOR TO SCAN'LAN-MORBIS COH- PANY, OF MADISON, WISCONSIN, A CORPORATION OF WISCONSIN ELECTRIC SWITCH Application filed October 5, 1929. Serial No. 397,706.

This invention relates to electric switches in general and particularly to electric switches for use in connection withthermosensitive means for operating the switch.

The object of the present invention is to provide an improved switch which is simple in construction, which is positive and efficient in operation, and which can be readily and economically manufactured.

Another object is to provide a quick acting snap switch, which is adapted to be manually closed, which is opened with a snap action by a thermo-sensitive element, and which has wiping engagement of the contacts for kee ing the contacts clean. Anot er object is to provide a snap switch which is provided with a double ad uStment for adjusting the movement of certain parts of the switch to move the switch operating mechanism toward or away from the element it operates.

A still further object is to provide a snap switch for use with thermo-sensitive elements, which has portions thereof extending below their normal horizontal axial center line to lock the'switch in closed position, during manual operation, and which is provided with spring tensioned means for opening the switch after said parts are moved above their normal horizontal axial center.

Numerous other objects and advantages will appear throughout the progress of the specification. J

The invention comprises in general a base plate upon which a vertical frame structure.

is rigidly attached. An angle lever is provided with a cross bus bar which has contacting relation with contacts fixed to the base of the s ring. A pair of links are operatively connected to the base of the spring structure and to the angle lever, which willingly supports the bus bar. The switch is manually operated and when so operated moves the links below their normal horizontal axial center line to lock the switch in contacted or engaged position. A pair of set screws are ad]ustably mounted in one of the links to cause quicker or retarded action of the switch during operation of a thermo-sensitive element.

The accompanying drawing illustrates a selected embodiment of the invention, and the views therein are as follows:

Fig. 1 is a detailed perspective view of the improved switch;

Fig. 2 is a detailed sectional view showing the switch in contacted but not locked position; and

Fig. 3 is a similar view showing the switch in contacted and locked position.

Referring to the drawing, 5 designates a plate or base having legs 6 for mounting the ase on a panel, box or other suitable'suportfl An upright frame 7 having side memvrs. and a top member 9 is fixed to the base, aii'dcarriesa shaft 10, which is mounted between the side members 8. An angle lever 11 having forwardly extending side legs 12, which are attached to the vertical arm 13 and a horizontal arm 14 is fixed to the cross shaft 10 by means of a set screw 15. An arm 16 carries a bus bar 17 which is mounted on top of the leg 14 of the lever 11, and a pin 18 extends through the arm 14 and through the arm 16 to provide a yieldin connection between the angle lever 11 an the arm 16 and bus bar 17.

Terminals 20 carrying contacts 21 are fixed to the base 5 and these contacts are adapted for engagement with contacts 22 fixed to the bus bar 17. Insulating material 23 is provided between the bus bar and the arm 16 to insulate these two members.

A spring 24 surrounds the shaft 10 and is fixed to one of the members 8 and to the angle lever 11 for normally urging the arm.

16 carrying the bus bar 17 upwardly or away from the terminals 20.

A handle or operating lever 25 havin a knob 26 extends through an. arm 27 which is fixed to the top member 9 of the frame 7. This operating lever carries a pin or trunnion 28, which engages the bifurcated end 29 of a link 30, which is pivotally mounted at 31 to the legs 12 of the angle lever 11. Another link 32 has one end pivotally mounted on the trunnion 28 between the bifurcated end 29 of the link 30 and its other end pivotally mounted at 33 ton yoke 34, which is rigidly mounted on the base 5. A set screw 35 threadingly engages the link 32 and extends through a hole 36 provided in the plate 5 when the switch is in closed or contacted position, Fig. 3. A thermo-sensitive element 37 having an operating finger 38, is adapted to bear against the end of the screw 35 for opening the switch to break the circuit. Operation of this screw moves the end thereof toward or away from the finger 38 to provide adjustment between these two members. A nut 39 threadingly engages the screw 35 for holding the same in adjusted position. A second set screw 40 threadingly engages the link 32 and has contacting relation with the base 5. Movement of this screw also limits the movement of the links 32 and 30 to increase or diminish the movement of the switch toward or away from the thermo-sensitive element 37. A lock nut 41 threadingly engages this screw to maintain the same in adjusted position.

In operation the operating lever 25 is moved downwardly or inwardly against the tension of the spring 24 to bring the switch into contacted or closed position. As the operating handle 25 is being moved inwardly, the contacts 21 and 22 will be in engagement, Fig. 2, but the contacts will not be exactly centered. Continued inward movement of the handle 25 causes the links 30 and 32 to move beyond their normal axial center line to the osition shown in Fig. 3 when the switch is in locked or contacted position. This continued movement brings the contacts 21 and 22 to centered position, the contacts wiping against each other during this continued pressure. The spring and pin connection or the arm 16 with the angle lever 11 provides relative movement of the links 30 and 32 and the wiping action of the contacts when the switch is in locked position.

During expansion of the thermo-sensitive element 37, the finger will move forwardly, to the right, Figs. 2 and 3, and push the screw 35 to the right until the links 30 and 32 pass their normal horizontal axial center line, and permit s ring 24 to pull the bus bar 17 away from t e contacts 21 on the terminals 20. By turning the screw 35, adjustment may be had between the switch and the thermo-scnsitive element 37, and by turning the screw 40 the movement of the links may be increased or diminished and thereby effecting sensitive adjustment of the switch.

The switch may be successfully used for making and breaking the circuit in a device, such as is shown and disclosed in the co pending application, Serial No. 397,705, filed concurrently herewith, and the thermo-sensitive element may be the type shown and disclosed in the aforesaid co-pending application. It is understood of Course that insulating material 42 is arranged between the terminals and the plate to insulate these terminals. 7

Changes may be made in the form, construction and arrangement of the parts without departing from the spirit of the invention or sacrificing any of its advantages, and the right is hereby reserved to make all such changes that fairly fall within the scope of the following claims:

The invention is hereby claimed as follows:

1. An electric switch comprising a base, contacts mounted on said base and insulated therefrom, a switch operating lever perpendicular to said base, a pair of alined links pivotally connected at their inner ends to said lever, and one of said links havin a pivotal connection with said support, a us bar, a support carrying said bar, a spring for urging the bus bar away from said base whereby inward movement of said lever will move said links below their normal horizontal axial center line to lock said switch in closed position, and resilient means connecting said us bar and its support for causing a wi ing connection between said contacts and sai bus bar, one of said links adapted to be moved to return both of said links beyond their normal axial center line to break electrical contact.

2. An electric switch comprising a frame, a support mounted on said frame, an angle lever connected to said support, an arm resiliently connected to said lever and carrying a bus bar, an operating handle, a pair of links pivoted to said handle. said operating handle moving said links below their normal axial center line for closing said switch, and means for causing a wiping action of said contacts during operation of the handle.

3. An electric switch comprising a frame, a support mounted on said frame, an angle lever connected to said support, an arm resiliently connected to said angle lever and carrying a bus bar. an operating handle, a pair of links pivoted to said handle. said links being moved below their normal axial center line for closing said switch upon operation of the handle, said contacts being resilient and constructed and arranged to provide a wiping action of said contacts when said handle is pushed inwardly. said switch being moved to open position when pressure is urged against one of said links.

4. An electric s itch comprising a frame, a support mounted on said frame, an angle lever connected to said support, an arm resiliently connected to said angle lever and carrying a bus bar, an operating handle, a pair of links pivoted to said handle, said links being moved beyond their normal axial center line for closing said switch when the handle is operated, means for causing a wiping action of said cputacts when said handle is moved inwardly, means for raising said links to return beyond their normal axial center line, and spring means for causing said bus bar to move upward with a. snap action when said links are returned beyond their normal axial center line.

5. An electric switch comprising a frame having an opening therethrough, an angle lever connected to said frame and having an arm, a bus bar, an arm connected to the bus bar, a spring connection between the arm on the angle lever and said last named arm for providing a yieldable connection between said last two members, an operating lever passing through said last named arm, a pair of alined links having their outer ends pivotally connected to a part of the switch and thelr inner ends pivotally connected to said operating lever, and means on one of said links and adapted to extend through said opening for engagement with a thermosensitive element when the switch is closed.

6. An electric switch comprising a frame having an opening therethrough,'an angle lever connected to said frame and having an arm, a bus bar, an arm connected to the bus bar, a spring connection between the arm on the angle lever and said last named arm for providing a yieldable connection between said last two members, an operating lever passing through said last named arm, a pair of alined pivoted links pivotally connected to said operating lever, a set screw passing through one of said links and adapted to extend through the hole in said frame for engagement with a thermo-sensitive element when the switch is closed by pushing inwardly on the handle, and a sec ond set screw operatively engaging said last named link and adapted to contact with said frame to limit the movement of said links in one direction.

7. A switch comprising a frame, a support carried by the frame, a shaft carried by the support, an angle lever pivotally mounted on the shaft, a bus bar operatively.connected to said angle lever, spring means for normally urging the bus bar in non-contacting position, an operating handle, a link pivotally connected to said handle and to said angle lever, a second link pivoted to the frame and to the handle, contacts carried by the frame, said bus bar adapted to make electrical contact with said contacts when. the handle is moved inwardly, the inward movement of said handle moving the links inwardly beyond their normal center line whereby the switch is maintained in locked position, and means adapted to engage one of said links lever, a second link pivoted to the frame and to the handle, contacts carried by the frame, said bus bar adapted to make electrical contact with said contacts when the handle is moved inwardly, the inward movement of said handle moving the links inwardly beyond their normal center line whereby the switch is'maintained in locked position, and

means carried by one of said links and adapted to be engaged by a member'when the their normal center line to cause disengagement of the bus bar from said contacts, said spring means moving the bus bar to original non-contacting position after the links have been returned past their normal center line.

9. A switch comprising a frame, a support carried by the frame, a shaft carried by the support, an angle lever pivotally mounted on the shaft, a bus bar operatively connected to said angle lever, spring means for normally urging .the bus barin non-contacting position, an operating handle, a link pivotally connected to said handle and to said angle lever, a second link pivoted to the frame and to the handle, contacts carried by the frame, said bus bar adapted to make electrical contact with said contacts when the handle is moved inwardly, the inward movement of said handle moving the links inwardly beyond their normal center line whereby the switch is maintained in locked position, and a screw threaded member threadedly engaging one of said links and adapted to be enaged by a member when the switch is closed or turning said links past their normal center line to cause disengagement of the bus bar from said contacts, said spring means moving the bus bar to original non-contacting position after the links have been returned past their normal center line.

10. A switch comprising a frame, a support carried by the frame, a shaft carried by the support, an angle lever pivotally mounted on the shaft, a bus bar operatively connected to said angle lever, spring means for normally urging the bus bar in non-contacting position, an operating handle, a link pivotally connected to said handle and to said angle lever, a second Link pivoted to the frame and to the handle, contacts carried by the frame, said bus bar adapted to make elec- "s 1.0"01 inwardly, the inward namesaid handie naNing the iinks iiibeyond their normal center line whereby the switch is maintained in locked msition, a screw: threaded member threadedly engaging one of said lin IS and adapted to be engaged by a member when the switch is closed for turning said links past their n0rmal center line to cause disengagement of the bus bar from said contacts said spring means moving the bus bar to original nonccntacting position after the inks have been returned past their normal center line and means for limiting the inward movement of said links.

In witness whereof, I have hereunto subscribed my name.

FLOYD BLASHFIELD.

III) 

